Overdrive control system



Sept. 28, 1943. E. M. CLAYTOR 2,330,407 I OVERDRIVE CONTROL SYSTEM Filed Aug. 15, 1939 ZSheets-Sheet 1 Z IhgZN/T ATTORNEY! Sept. 28, 1943. E. M. CLAYTOR 2,330,407

'OVERDRIVE CONTROL s smm Filed Aug. 16, 1939 3 Sheets-Sheet 2 g 7 gqysnfon %a ATTORNEY P ,1943. v E. M. CLAYTOR I 2,330,407

OVERDRIVE CONTROL SYSTEM Filed Aug. 16, 1,959 .3 shget's-sheet 5 INVENTOR K ATTORNEYAJ a Patented Sept. 28, 1943 ovnanmvn CONTROL SYSTEM Edward M. Claytor, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application August 16, 1939, Serial No. 290,356

38 Claims.

This invention relates to electrically operated means for controlling the overdrive gearing for an automotive vehicle. One type f overdrive with which the present invention may be used is one in which a shaft transmitting power from the change speed gearing of the automobile may a be connected with the propeller shaft for a 1 to 1 gear ratio drive or indirectly through planetary gearing of the overdrive by means of which the propeller shaft is caused to rotate faster than the drive shaft. The planetary gearing includes a sun gear which rotates with the drive shaft when the overdrive is not operative. To render the overdrive operative, the sun gear must be held stationary. In my copending application S. N. 241,917, filed November 23, 1938, I disclose an overdrive control in which the sun gear locking pawl is urged normally into locking position by a spring in which the locking pawl is retracted by the operation of a solenoid. In order to facilitate retraction of the sun gear locking pawl by the solenoid I provide a relay which opens the ignition circuit momentarily until the solenoid has completed its operation. The opening of the ignition circuit causes the engine to cease firing until the sun gear latch or pawl is withdrawn, whereupon the normal firing is reestablished.

The present invention relates more particularly with an overdrive controlled by a sun gear locking pawl which is actuated by the solenoid int locking position and by a spring out of locking position. The present invention is concerned with momentarily opening the ignition circuit during the time in which the sun gear locking pawl is retracted by spring operation. In one form of embodiment of my invention I control the time during which the ignition circuit is interrupted by means of electromagnetic relay which operates to maintain the ignition circuit open for a measured time after the solenoid circuit is interrupted. This measured time is controlled by the relay and is independent of the movement of retraction of the sun gear locking pawl. The time delay is greater than the time required under all normal conditions for the sun gear locking pawl to be withdrawn. In case the pawl is not retracted for any reason, such as failure of the return spring, the sticking of the pawl due to heavy, cold lubricant or due to excessive negative pressure as when going down a long grade, the relay completes the ignition circuit in any event.

In another form of embodiment of my invention I combine, with the time measuring relay,

a switch actuated in response to the return of the pawl to fully retracted position for reestablishing the ignition circuit. In this way I am able to reduce the time during which the ignition is nonoperative to the minimum requirements while, at the same time, providing for the ultimate reestablishment of the ignition circuit in case of failure to retract the sun gear locking pawl.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown.

In the drawings:

Fig, 1 shows a diagram of an overdrive to which the control of my present invention is applied, said control being illustrated by a wiring diagram forming a part of Fig. 1.

Fig. 1a is a diagram showing the sun gear locking pawl and pawl blocking member which has been moved to position to permit movement of the pawl into engagement with the sun gear locking ring.

Fig. 2 is a longitudinal sectional view of the pawl controlling solenoid.

Fig. 3 is a view looking in the direction of the arrow 3 of Fig.2, the solenoid cover being removed.

Fig. 4 is a view looking into the direction of. the arrow 4 of Fig. 2 showing the assembly of solenoid magnet cup and cup cover plate carrying certain terminals and switch elements.

Figs. 5 and 6 are fragmentary views looking in the direction of the arrows 5 audit of Fig. 4.

Fig. '7 is a fragmentary view of a portion of the solenoid armature and certain adjustable nuts associated therewith.

Fig 8 is a wiring diagram showing a modified form of the invention.

Fig. 9 is a View sirrii-lar to Fig, 3 showing modifications of construction necessary to take care of certain circuits shown in Fig. 8.

Figs. 10 and ll-are fragmentary sectional views taken on the lines l0|0 and H-H respectively of Fig. 9.

Referring to Fig. 1, numeral l indicates the V 9. The external splines 2 mesh also with internal splines 8a of a coupling member 8 to which the propeller shaft 8b may be attached. The splines 2 connect together the members 3 and 9 as shown in Fig. 1, when it is desired to use the overdrive mechanism. When it is not intended that the overdrive mechanism shall be used for any considerable period of time, the overdrive may be entirely disconnected by moving the shaft I endwise toward the left so that its external splines 2 will engage the internal splines 8a of the'member 8, thus connecting together the members 8 and 9 and leaving the members 3 free. The shaft I is supported for axial movement at both ends. The support for the right hand end of the shaft I is not shown. At the left end of the shaft I it is provided with a reduced portion Ia having a sliding fit within an axially aligned recess 8c provided in the member 8.

The ring 3 carries a plurality of rods 4 each rotatively supporting a planet gear which meshes with a sun gear 6 and with an internal ring gear 1a integral with ring 1, which cooperates with the clutch rollers I0, which in turn cooperate with a driving clutch cam 9 to receive transmission of torque from the driving member at such time as the driving member 9 tends to rotate ahead of the member 1. However, when a ring I I attached to the sun gear 6, is engaged by a sun gear locking pawl 22 which is received by one of a series of notches I2 in ring I I, the internal ring gear 1a and its ring 1 are driven at a speed exceeding the speed of the clutch driving member 9. Under these conditions the ring 1 will overrun the clutch driving member 9. The pawl 22 is normally maintained out of engagement with the ring II by a pawl rod 23 which is controlled in a manner to be described. Move- J ment of the pawl 22 into engagement with the ring II is obstructed, except under certain conditions, by a blocker plate l3 which is frictionally dragged by ring II. The blocker plate I3 is provided with stop lugs I4 and I5 which project beyond stop surfaces I6 and I1 which may be engaged under certain conditions by the pawl 22. The surfaces I6 and I1 are interrupted by a notch I8 of sufiicient width to permit movement of the pawl 22 between the surfaces I6 and I1 when the notch I8 is brought into alignment with the pawl 22, as shown in Fig. Ia. The pawl 22 is guided between bosses I9 and 20 of the frame 2| of the overdrive mechanism. Bosses I9 and 20 project into the plane of the blocker plate I3 so as to be engaged by lugs I 4 and I5, respectively. When the ring II rotates clockwise, the blocker plate I3 will be frictionallydragged clockwise until its lug I4 strikes the boss I9, and further movement of the blocker plate I3 in the clockwise direction will cease. When the ring iI rotates counterclockwise, the blocker plate I3 will be frictionally dragged counterclockwise until its lug I5 engages the boss 20 whereupon counterclockwise movement of the plate I3 will cease. An explanation of the clockwise and counterclockwise movements of the ring II will be given in connection with the mode of operation of the control device which controls the overdrive gear- The sun gear locking pawl 22 is attached to a pawl rod 23 extending through a solenoid stationary core 24 and through a solenoid armature 25. Rod 23 has a shoulder portion 26 located within a recess 21 provided by the armature 25.

Referring also to Fig. 2 it will be seen that the solenoid core 24 extends through a magnetizable washer 28 and the end wall of the magnetizable solenoid cup 29. The right hand end portion of the core 24 provides a pilot extension 24b which is received by recess 30 in a bracket 3| which carries a packing unit 32 thru which the rod 23 is slidable. The cup 29 is attached to a mounting plate 33, which, together with the bracket 3| may be attached to the frame 2| of the overdrive by bolts, not shown, which pass thru the aligned holes 330. and 3Ia of the plate 33 and bracket 3|. Parts 33, 29, 28 and 24 are welded together.

The cup 29 is counterbored at 34 to provide a shoulder against which there rests a cover plate 35 which is centrally apertured to receive a bushing 36. The bushing 35 and the plate 35 are of magnetizable material. The bushing 36 and the core 24 support a thin wall non-magnetizable tube 31 which supports the solenoid armature 25 for sliding movement toward or away from the core 24. The armature 25 is provided with a conical recess 25a and the core 24 with conical pole face extension 24a mating with the recess 25a. This construction places the air gap more nearly central with respect to the solenoid windings 4D and 4| which surround the tube 31 and which are confined between non-conducting washers 43 also supported by the tube 31. This armature and core construction provides greater sliding surface for the armature than would be had by the conventional construction of placing the conical recess in the core.

The shoulder member 26 for the rod 23 is provided by non-magnetizable bushing 45 secured to the rod by pin 46. The armature 25 has a threaded portion which receives an adjusting nut 41. The nut 41 is provided with an inwardly extending annular flange 41a against which bears one end of a spring 59, bearing at its other end against the shoulder portion 26 of the bushing 45. The initial compression of the spring is obtained by the proper adjustment of the nut 41 which is locked in adjusted position by a single turn spring 5|, see also Fig. '1, having one end received by a hole 52 provided by the armature 25 and the other end by one of a plurality of notches 53 provided by the nut 41. To unlock the nut 41 the spring 5| must be withdrawn from the notch 53. The position of the nut 41 along the armature 25 can be adjusted after an end of the spring 5| has been withdrawn from the notch 53 in the nut 41. By adjusting the nut 41 along the armature 25, the location of the rod 23 normally with respect to the stationary parts can be varied; therefore the normal position of the pawl 22 relative to the blocking member I3 can be varied.

A spring 55, surrounding the armature 25 and located between the flange 41b of the nut 41 and the plate 35 urges the nut 41 toward the left against a leather bumper plate 56 secured to a mounting plate 51 which is supported by a plurality of studs 58 threaded into the plate 35. Plate 51 is secured on studs 58 by nuts 59. Since the spring urges the nut 41 into the position shown in Fig. 2, the armature 25 and the rod 23 are consequently held in the positions shown in Fig. 2.

The plate 35 insulatingly supports a bracket 60 carrying a contact 6| normally engaged by contact 62 carried by a resilient conductor 63 mounted directly upon the plate 35 and therefor grounded as indicated in Fig. 1 at the right.

The contact supporting member 63 has a projection 630 located in the path of movement of the flange 41b of nut 41. Bracket 60 is connected with one end of solenoid magnet winding 40, the other end of which is connected with an insulated terminal 64. The winding 40 which is composed of a relatively small number of turns of coarse wire is the main attracting coil of the solenoid. The winding 4| which is grounded at one end and connected at the other with an insulated terminal 65, is the holding coil of the solenoid. It comprises a relatively large number of turns of fine wire.

The rod 23 carries a contact button 66 engageable with a contact 61 mounted on the end of a resilient conductor 68 insulatingly supported on the plate 51 and joined by a rivet 69 with a bracket I0. These contacts and terminals are enclosed by a cover II the peripheral edgeof which bear. against a shoulder I2 provided by the shell 29. The cover II is secured in position by nuts I3 engaging the threaded ends of the studs 58. The brackets 64-65 and I respectively cooperate with Wire attaching screws 64a65a and a. passing thru bushings I4 insulatingly supported by the cover I I.

The rod 23 which is magnetizable is provided with a neck or reduced portion 23a so that this portion of the rod 23 will become readily saturated with magnetic fiux. This construction tends to prevent the straying of flux from the poles of core 24 and armature 25 and make the solenoid operate more efficiently. Freedom of movement of the armature 25 is provided by vent 240 in core 24 and vent 3Ib in bracket 3I.

Referring to Fig. 1, a generator 80 is connected thru the reverse current relay 8| and an ammeter 82 and a wire 83 with a storage battery 84. Wire 83 is connected by wire 86 with a terminal 81 of a relay 85. Terminal 81 is connected with a stastationary contact'88 adapted to be engaged by a normally separated contact 89 carried by an armature 90 fixed to a bracket Ellwhich is connected with a relay terminal 92. Terminal 8'! is connected with relay magnet winding 93 connected with terminal 94. Armature 96 carries a contact 95 adapted to engage normally separated contact 96 connected by wire 91 with bracket 98 of a relay I00 having a magnet Winding IOI connected by wire I02 with terminal 92 of relay 85. Winding IOI supports a core IOIa cooperating with an armature I03 carrying a contact I04 normally engaging contact I05 connected by wire I06 with terminal 81 to relay 85. Bracket 98 of relay I00 is connected by wire I01 with ignition switch I08 connected with an ignition coil I09 having a secondary H0 and a primary, I II connected with grounded ignition timer H2. Winding IIlI of relay I00 is connected by wire II3 with solenoid terminal 65. Solenoid terminal 64 is connected by wire II4 with terminal 92 of relay 85. Terminal 92 is connected by wire II5 with an indicator lamp II6 which maybe grounded at In. Instead of grounding the lamp H6 at IIT it ma be connected with ground by wire I I8 connecting noid armature 25 toward solenoid core 24.

I22 adapted to be bridged by movable contact I23 held out of engagement with the stationary contacts by spring I24. The gear switch I20 is closed by mechanism which is actuated when the transmission gear shaft lever is-in intermediate position or in high speed position. Switch I20 is connected with a kick switch I25 comprising stationary contacts I26 and I21 normally engaged by contact I28 held normally in contact closing position by a spring I29. The switch I25 is opened by a suitable pedal cooperating with switch actuating rod I25a. This pedal may be the engine accelerator pedal which causes the switch I25 to open by movement of accelerator pedal beyond wide open throttle position. Switch I25 is connected with ground thru a switch responsive to vehicle speed such as an air switch I30 having a grounded vane I3I pivoted at I32 and maintained normally out of engagement with contact I33 by the action of a spring I34. The vane I3I is moved into engagement with contact I33 by the action of an air current provided by, the engine coolin fan I35 causing a current of air to impinge upon the vane I3I as indicated by the arrow I36.

The operation of the overdrive system illustrated by Fig. 1 is as follows: While the engine is running the ignition switch I08 will be closed. When the vehicle transmission is set for drive thru intermediate gears or high speed gears the switch I20 .will be closed. When the vehicle speed maintains acertain value such as 25 m. p. h.

' for example, the air switch I30 will be closed. As

stated before, switch I25 is normally closed. All three switches I20, I25 and I36 being closed, the winding 93 of relay will receive current from the battery 84 thereby causing armature 96 to be attracted and contacts 89 and to engage contacts 88 and 96 respectively. When this occurs solenoid magnet winding 40' will be connected with battery 84 through the circuit which includes wires 83 and 86, contacts 88 and 89, armature 90, bracket 9|, terminal92 wire I I4, terminal 64, winding 40, contact bracket 60, contacts BI and 62, contact arm 63. Through a branch circuit which includes terminal 92, wire I02 winding IOI of relay I00, wire H3, terminal 65, the solenoid winding M will be connected with battery 84. Both windings 40 and M cooperate to attract sole- As armature 25 goes downwardly it carries with it the nut 41 which forces the upperend of the spring 50 downwardly thereby tending to 'move the rod 23 downwardly.

When the solenoid is not excited, the spring 55, acting through the pawl rod 23, keeps pawl 22 out of engagement with the blocker plate I3. When the engine drives the transmission, the ring II moves counterclockwise as viewed in Fig. 1A and the'plate I3 isfrictionally dragged counterclockwise so that its lug I5 engages boss 20 thereby causing surface Il to be in the path of movement of the pawl 22. When the engine speed is increased to the speed where the governor switch I30 closes, the hand controlled change speed gearing being in intermediate or high gear, the solenoid will be energized in the manner described. The pawl 22 is then urged downwardly by .spring 50 and presses against surface. I'L Engagement of the pawl 22 with the notched locking ring II is prevented until the speed of ring II is reduced to zero and the rotation of ring II reverses.

The reversal of ring II is effected by a reduction of engine speed (measured in miles per hour of vehicle speed) below vehicle speed by a predetermined amount dependent upon the gear ratio of overdrive to normal drive. For example, if the overdrive increases speed ratio between vehicle drive wheels and the engine by 30%, the engine speed must be reduced below vehicle speed by the amount of 30% of vehicle speed. Assuming the vehicle is being propelled through normal drive at 40 In. p. h. and it is desired to go into overdrive, the driver releases the accelerator pedal to permit engine speed to decrease. The vehicle free wheels (through overrunning clutch 9-I0) at a speed starting at 40 m. p. h. and diminishing slightly due to resistance of wind and friction to about 35 m. p. h. Meanwhile the engine speed has diminished to 24 m. p. h., which speed is slightly more than 30% lessthan 35 m. p. h., the concurrent vehicle speed. As the engine speed decreases to 24 In. p. h., the speed of ring II is reduced to zero and then the ring lI starts to reverse in direction of rotation or to move clockwise as viewed in Fig. 1A. As ring II begins to move slowly clockwise, it drags frictionally the blocker plate I3 clockwise thereby causing its lug I5 to move away from the boss 20 and its notch I8 to become aligned with pawl 22 thereby permitting spring 50 to press pawl 22 against a tooth of ring II. As ring II continues to rotate, it brings a notch I2 into alignment with pawl 22 thereby permitting spring 50 to press pawl 22 into locking engagement with the ring II thereby locking sun gear 6. While the sun gear 6 is locked transmission of power from the shaft I to the shaft 81) takes place through the elements 2, 3a, 3, 4, 5, 1a, 1 and 8. The sun gear 6 being stationary, the ring gear 1a rotates faster than shaft I. Since parts 9 and 1 are connected through a one-way clutch represented by the numeral I0, the ring Toverruns the shaft I while the overdrive is affective.

During movement of the solenoid armature 25 the core 24 in order to preload the spring 50 so that it may push the pawl 22 into a notch I2 of the sun gear locking ring II when the blocker I3 is retracted, the flange 41b of nut 41 engages the projection of resilient contact 63 thereby separating contact 62 from contact BI and breaking the circuit thru the main attracting coil 40 of the solenoid. The armature 25, being then in relatively close proximity with the core 24, is held in the attracted position by the holding coil 4 I.

The normally closed contacts I04 and I05 of relay I provide a connection between the battery 84 and the ignition switch I08, when the contacts of relay 85 are separated. When the contacts of relay 85 are closed, a by-pass circuit -to the ignition switch I08 is completed around contacts I04 and I of relay I00. This by-pass starts from terminals 81 and includes contact 88 and 89, armature 90, contacts 95 and 96, wire 91 and bracket 98. While relay 85 is energized to maintain this by-pass, relay I00 is also energized to interrupt the connection to the ignition switch by separating contact I04 from contact I05.

When the driver desires to render the overdrive inoperative. he presses the kick switch rod I25a to interrupt the flow of current thru the relay winding 93 whereupon the armature 90 returns to normal position separating contacts 89 and 95 from contacts 88 and 96 respectively. This interrupts the fiow of current thru the relay magnet IM and the solenoid armature holding coil 4! thereby permitting relay I00 and the solenoid armature 25 to return to normal condition. When holding coil M is deenergized, spring 55, by operating thru the nut 41, and the nut 31, by operating on the shoulder 26 causes the pawl rod 23 and the pawl 22 to be restored to normal position shown in Fig. 1. During upward movement of the nut 41 the resilient contact support 63 is relieved by engagement of the flange 41b of the nut 41 thereby permitting the contact 62 to reengage the contact 6I.

A predetermined time after the separation of the contacts of relay 85, the contact I04 of relay I 00 returns into engagement with the contact I05. This predetermined time is measured or determined by the characteristics of the relay I00. The lag or time delay between the opening of contacts 95 and 96 of relay and the closing of contacts I04 and I05 of relay I00 is effected by causing the armature 93 to seal against the core IOIa of relay when its contacts are open thereby making it necessary for the magnetic flux in the care IOIa to diminish to substantially zero before the armature I03 is released. The decay of flux in the core I0la is retarded by a short circuited coil IOIb. During this measured time interval between the opening of contacts 95 and 96 of relay 85 and the closing of contacts I04 and I05 of relay I00, current to the ignition coil I09 is interrupted, thereby eliminating the igniting of several fuel charges whereby the engine ceasesto drive the vehicle and the torque reaction between the sun gear locking ring II and the pawl 22 is relieved in order to facilitate retraction of the pawl 22 by the spring 55.

If the signal lamp H6 is grounded at Ill and the circuit, shown in dot-dash lines thru the solenoid is omitted, the lamp IIB will burn as long as the relay 85 is closed. Under these cireumstances the lamp IIS burns to indicate that the overdrive is operative. If the ground H1 is omitted and the circuit includes the parts indicated in dot-dash lines, the lamp II6 will burn to indicate that relay 85 is operative and therefore the solenoid armature 25 has been attracted to preload the pressure spring 50. When the driver releases the accelerator pedal to permit the vehicle to drive the engine and to effect the retraction of the blocker I3, then the pawl 22 will move into engagement with the sun gear looking ring II. During such movement of the pawl 22, the circuit thru the signal lamp IIS will be interrupted by the separation of contacts 66 and 61. Therefore, when the circuit thru the signal lamp II6 omits the ground H1 and includes wire H8 and contacts 66 and 61, the burning of the lamp II6 indicates operation of the relay 95 to precondition the solenoid for overdrive operation, and the subsequent ncn-burmng of the lamp II6 indicates that the overdrive has been rendered operative.

From the foregoing description of the construction and mode of operation of a control circuit embodying the first form of my invention it is apparent that I have provided electromagnetic means operating independent of the solenoid for causing the ignition circuit to be interrupted for a predetermined interval of time sufficient to enable the return spring 55 of the solenoid to operate to retract the pawl 22 while the torque reaction is relieved between the pawl 22 and the sun gear locking ring II. In any event, the time delay afforded by the relay I00 is greater than the time required under all normal conditions for the retraction of the pawl 22. In case the pawl 22 is not retracted for any reason such as failure of the return spring 55, the relay I08 completes the ignition circuit.

Since it might be objectionable to some car drivers to allow the ignition circuit to remain interrupted longer than absolutely necessary for retraction of the sun gear locking pawl, I provide in the second form of my invention, illustrated by Figs. 8 to 11, the combination of a time measuring relay, which completes the ignition circuit in any event, and another switch for completing the ignition circuit in response to the complete retraction of the sun gear locking pawl,

Referring to Fig. 8 a storage battery I40 is connected with ground and with a wire l4l from which wire leads oil to a green indicator lamp 142 connected with a terminal I43, and a wire leads off to a magnet winding I44 of a relay I45 said winding being connected also with terminal I43.

Wire I4I is connected with contact I5I of a relay I50 which, in this form of invention, is the time measuring relay. Contact I5I is normally engaged by a contact I52 carried by an arma-' ture I53 attached to support I54. The relay I50 includes a magnetizable core I55 surrounded by a magnet coil. I56 connected with wire I51 and with ground. The core I55 issurrounded by a single turn short circuited coil I58 for the purpose of retarding the delay of flux of the relay in order to delay the return of contact I52 into engagement with contact I 5|.

Relay I68 includes a magnet winding I6I connected with wire I 4| and with a;-terminal I62. Winding I6I surrounds the core I63 which cooperates with an armature I64 attached to a support I65 and electrically connected with contacts I66 and I61 engageable, respectively, withtstationary contacts I68 and I69. Contact I68 is connected with wire I4I. Contact I69 is connected by wire I10 with support I54 of relay I50. Armature I64 insulatingly supports a bracket I1I carrying a contact I12 for engaging a contact I13 connected with wire MI. The bracket MI is connected with wire I51. Armature bracket I65 of relay I60 is connected by wire I15 with the solenoid terminal 54 to which main attracting coil 40 is connected as was the case in Fig. 1. In Fig. 8 however, the holding magnet coil M is connected with the same terminal 54.

To the wire I15 is connected a red signal lamp I16 which is grounded. Lamp I16 burns to indicate operation of relay I60 and, therefore, operation of the solenoid unit. The terminal I62 of Fig. 8, which corresponds to terminal 84 of Fig. 1, is connected in series with the gear shift responsive switch I20, the accelerator pedal op. erated switch I25 and the vehicle speed responsive switch I30. The armature bracket I54 of relay I50 is connected by wire I11 with ignition switch I08. The terminal I43 is connected by wire I18 with, a terminal I19 connected with a resilient switch arm I80 carrying a contact I8I forengaging a grounded contact I82. Contact I8I is normally held apart from the contact I82 due to the fact that the contact support I80 engages a nonconducting button I83 mounted on the upper end of the pawl rod 23. The terminal I19 corresponds in position to the terminal 10 of Fig. 3 and the resilient support I80, to the support 68 of Fig. 3. As shown in Figs. 10 and 11, contact' I82 is mounted on a resilient support I82a which is directly attached to the plate 51 by the rivet 56a which secures the plate 51 and bumper plate 56 together.

The operation of the circuit shown in Fig. 8 is as follows: Before going. into overdrive, switches I20 and I30 must be closed as in the case of the form of invention shown in Fig. 1. To go into overdrive the driver releases the accelerator pedal to permit a reversal of torque transmission in order that the blocking member I3 will move into position to permit the pawl 22 to enter a notch I2 of the sun gear locking ring'I I.

The closing of the switches I20 and I30 establishes a circuit between the battery'I40 and coil I6I of relay I60 thereby causing the armature I64 to move downwardly in order to establish connections between the pairs of contacts I12I'I3, I66--I68 and I61-I69. of contacts I66-I68 establishes a circuit from the battery to the coils 40 and H of the solenoid thereby causing the armature 25 to move downwardly toward the core 24 in order to preload the spring 50 which, when the blocking member I3 releases-the pawl 22, causes the pawl 22 to engage the sun gear locking ring I I. During downward movement of the armature 25, the nut 41 engages contact arm 63 to separate contact 62 from contact 6I thereby interrupting the circuit of the main winding 40. Current, however, continues to flow thru the holding coil winding 4I thereby maintaining the armature 25 in proximity to the core 24 and the spring 50 under sufli. cient compression to maintain the pawl 22 in engagement with the sun gear locking ring II.

The closing of contact I66 and I68 establishes a circuit to the red signal lamp I16 which indicates that current is flowing thru the solenoid windings 40 and 4i and, therefore, that the pawl rod 23 operating spring 50 is being pre-loaded for movement of the-pawl 22 into sun gear locking position prior to the unblocking of the pawl. As soon as the pawl is unblocked by movement of the locking member I3, the pawl rod 23 will move downwardly under the action of spring 50 thereby permitting the closing of contacts IBI and I82 which establishes a circuit to the green signal light I42 th burning of which indicates that the overdrive has been established.

The closing of contacts I8I and I82 also establishes a circuit to the winding I44 of relay I45 thereby causing the opening of contacts I46 and I41. For purposes to be. described later these contacts will'remain open during overdrive and until the pawl 22 has been substantially completely retracted.

The closing of contacts I66I68 and I61I69 of relay I60 establishes a circuit to the ignition coil I09 paralleling a circuit provided by contacts I 5| and I52 and armature I53 of the measured time relay I50. The movement of armature I64 of relay I60'which closes contacts I66-I68 and ,I61I69,alsc closes contacts I12-I13 thereby completing a circuit to winding I56 of measured time relay I50. Since relay I50 has its coil I 56 fed from contacts I12 and I13 of relay I60, the ignition circuit remains unbroken during the operation of the system to establish the overdrive, because contacts I5I and I52 cannot open before contacts I12 and I13 close.

To come out of overdrive the car driver opens the switch I25 which may be controlled by movement of the accelerator pedal beyond wide open throttle position. The opening of switch l25 interrupts the-circuit of the winding I6I of relay I60 whereupon armature I64 moves upwardly The closing and all pairs of contacts of relay I60 are separated. Ther is therefore no ignition since at that time, the contacts of relay I50 and the contacts of relay I45 are also separated. Therefore there is no torque developed by the engine and the frictional resistance to the retraction of the sun gear locking pawl 22 is removed thereby permitting the spring 55 to operate as in the case of Fig. l to retract the pawl. As soon as the pawl 22 is fully retracted by upward movement of the rod 23 the contact I8I is separated from the contact I82, thereby interrupting the flow of current thru the green light M2 to indicate that the car is out of overdrive. The extinguishing of red light I16 indicates the operation of the system for the purpose of coming out of overdrive.

The opening of contacts I8I and I82 also causes deenergization of relay magnet winding I44 thereby permitting contacts I46 and I41 to close in order to reestablish the circuitbetween the battery I40 and the ignition coil I09. However at this instant the contacts of relay I50 are still open due to the fact that, altho the circuit of magnetwinding I56 has been broken by the opening of the contacts I12 and I13 of relay I60, nevertheless there is a delay in the reelosing of these contacts I5I and I52. This delay is efifected by an adjustment of relay I50 which allows the armature I53 to be sealed against'the end of the core I55 when the armature I53 is attracted; and this delay may be effected also by retarding the decay of flux in core I55 by the short circuited coil I58. As was the case of relay I of Fig. 1, the measured time provided by relay I50 between the opening of switch I25 of the closing of contacts II and I52 is greater than the time required under all normal conditions for the sun gear locking pawl 22 to be retracted. In order that the ignition will not be interrupted any longerthan. necessary the relay I45, on becoming deenergized by the return of pawl rod 23 to uppermost position, permits the reestablishment of the ignition circuit by the closing of contacts I46 and I41. Obviously these contacts close ahead of the closing of contacts I5I and I52 of the measured time relay I50. However, in the circuit shown in Fig. 8, the relay I50 still serves a useful purpose since, in the event that the sun gear locking pawl were not retracted, due to failure of the return spring 55 for example, then the contacts of relay I45 would always remain open but the relay I50 would eventually step in to reestablish the ignition system so that the engine would operate although the car still remained in overdri've.

From the foregoing description of the construction and mode of operation of the disclosed embodiments of the present invention, it is apparent that I have provided the combination with a sun gear locking pawl normally held out of locking position by a spring of a solenoid for actuating the pawl into locking position, said solenoid being controlled automatically in response to vehicle speed and in response to movementbf the transmission gear shift lever into intermediate or into high position, means under pawl to non-locking position. This last named means functions automatically to restore the ignition to operative condition a measured time interval after operation of the means which renders the solenoid inoperative. Since there is a time interval of appreciable duration between the rendering of the ignition inoperative and the restoration of the ignition to operative condition, I have brought about two separate instances where conditions are favorable to the retraction of the pawl from sun gear locking position by the pawl returning spring.

Let us first consider the instance where the ignition is rendered inoperative. It will be understood there is a certain amount of lost motion or side-play-between the pawl 22 and the sides of a notch I2 of the locking ring II. While the engine ignition is operative and the engine drives the vehicle, the torque transmitted by the engine to the vehicle drive wheels is what I term as positive torque. When the engine ignition is rendered inoperative, the vehicle tends to drive the engine and the transmission of torque is reversed. I designate this reversed torque as negative torque. When positive torque is present the pawl 22 will press against one side of a notch l2 and, when negative torque is present, the pawl 22 will press against the other side of the notch I2. It is obvious that, if 'the ignition is rendered inoperative causing the engine to cease to fire, the torque will change from positive to negative and the pawl 22 will move from a position where it presses against one side of the notch I2 to a position where it presses against the other side of the notch. During the period of time of relative side-wise movement between the notch I2 ,and the pawl 22 in which the pawl 22 relatively moves from one side of the notch I2 to the other, there is a condition where there is no binding force between the ring II and pawl 22 to resist withdrawal of the pawl 22 by the pawl return spring 55. This change from positive torque to negative torque produces a condition which is favorable to the retraction of the pawl 22 from the ring II. Obviously the duration of this condition is relatively short, since it continues only long enough for the pawl to leave one side of the notch, traverse the lost motion space between the sides of the notch and then engage the opposite sides of the notch. Under some unusual circumstances, this period of short duration might not be sufiicient for the pawl 22 to be completely withdrawn from the sun gear locking ring II. However, another instance of favorable conditions for retraction of the pawl 22 by the spring 55 is afforded. 1

At the end of the measured time interval provided by relay I00 during which the ignition may be inoperative, there is another condition of no binding between the pawl 22 and ring II at the instant when the ignition apparatus is rendered operative, because there is another reversal of torque from negative torque to positive torque.

Therefore, the present invention provides two inthe control of the operator for rendering the solenoid inoperative and also for interrupting the power feed circuit of the ignition system so that conditions are produced which are favorable to the retraction of the pawl by the spring, and means for restoring the ignition to operative condition independent of any control by the driver and independent of any movement of the 'stances which are favorable to the retraction of the pawl 22 of the sun gear locking ring Ii. Therefore, there are two opportunities for the pawl 22 to be'retracted.

While'the embodiments of the present invention as herein disclosed, constitute preferred forms, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. An overdrive control for automotive vehicles current source andthe ignition apparatus "said contacts being opened upon energization of the magnet coil of said measured time relay, normally open contacts closed by the main control relay and operative when closed to complete a circuit between the current source and ignition apparatus independently of the contacts of the measured time relay, normally open contacts closed by the main control relay and operative when closed to complete a circuit between the'current source and the magnet coil of the measured time relay, and means for controlling the circuit between the current source and the magnet coil of the main control relay.

2. An overdrive control according to claim 1 in which the lag of the measured time relay is effected by having its relay armature seal against its core when the armature i attracted.

3. An overdrive control according to claim 1 in which the lag of the measured time relay is effected by providing its core with a short-circuited damper winding.

4. An overdrive control according to claim 1 in which the solenoid is provided with an armature main attracting coil and an armature holding coil and with a switch for open-circuiting the main-attracting coil in response to movement of the solenoid armature, and in which the holding coil of the solenoid is in series with the magnet coil of the measured time relay.

5. An overdrive control according to claim 1 in which a signal is provided to indicate operation of main control relay to effect operation of the solenoid.

6. An overdrive control for automotive vehicles comprising the combinationof a current source,

a'solenoid for urging the, sun-gear-lockingpawl or an over-drive mechanism into looking engagement with thesun-gear thereof, a main control relay for controlling the circuit between the current source and the solenoid, engine ignition apparatus, a measured time relay having normally closed contacts controlling/the circuit between the current source and the ignition apparatus, said contactsbeing opened upon energiz'ation of the magnet coil of said measured time relay, normally open contacts closed by the main control relay and operative when closed to complete a circuit between the current source and ignition apparatus independent of the contacts of the measured time relay, normally open contacts closed by the main control relay and operative when'closed to complete a circuit between the ured time relay, a third relay having normally closed contacts parallelling the contacts of the measured time relay, said contacts being opened upon energization of' the magnet coil of said third relay, a switch closed in respo seto movement of the latch into sun-gear; ocking position for connecting the magnet coi of the third relay with the current source, and means for controlling the main control relay.

'7. An overdrive control according to claim 6 in which a signal is provided to indicate opera-- in which a signal is provided to indicate that the pawl has locked the sun-gear.

-9. An overdrivecontrol according to claim 6 in which a signal lamp of one color burns to in- 5 dicate operation of the main controllrelay to effect operation of thesolenoid, and in which a signal lamp of another color burns to indicate that the pawl has locked thesun-gear.

10.-An overdrive control for-automotive vehicles comprising a pawl for locking the sun-gear of the overdrive mechanism, means-'forueffecting actuation of the pawl, engine ignition appa- -rat-us,-a current source, a normally closed switch for connecting the ignition apparatus with the current-source, a normally open switch controlled by the means for effecting actuation ,of the pawl for paralleling the normally closed switch and operating when closed to connect the i nition apparatus with the current source independentl of the normally closed contacts, a measured time relay for controlling the normally closed switch and having a magnet winding which, when energized, causes the opening of the normally closed contacts, and'a switch controlled by.

-tion withmeans for controlling the pawl of a -normally open'switch'for connecting engine ignition apparatus with a-currentsource. means for effecting the closing of theswitch when the pawl is urged toward locking engagement with the sun gear, a normally open switch paralleling the normally closed switch also forconnecting the ignition apparatus with the current-source.

45 a measured time relay for opening the normally closed switch'and having a magnet winding, and means for connectingthe magnet winding with the current source when the pawl is urged toward locking engagement with the sun gear, the

0 first mentioned switch being openedand the circuit of the magnet winding being openedfwhe n Q the pawl is released for movement out of engagement with the sun gear,

13. The combination of claim 12 with-the ad- 5 dition of a switch responsive toretraction of the p wl from the sun-gear for connecting the current source with the ignition apparat s. 14. In a system of controlling an overdrive for automotive vehicles, the:combination of a 60 magnetizable sun-gear locking-pawl rod a tubucurrent source and the magnet coil of the measlar magnetizable core and a tubular magnetizable armature through which the rod extends, said rod having a reduced portion in the region of the pole faces of the core and armature, elec- 55 tromagnetic windings for creating magnetic flux,

therod cooperating with the core and armature to minimize flux leakage, said reduced .portion of the rod becoming saturated whereby a substantial part off'the flux threading within the 70 windings is caused to pass through the gap between the core and armature, and means for transmitting movement between the armature and rod.

15. The combination of claim 14 further char- 7 acterized by including withthe movement trans.

mitting means a non-magnetizable member attached to the rod and adapted to bear against a portion of the armature.

16. The combination of claim 14 in which the armature is provided with an internal, frustoconical pole face defining a recess for receiving an external frusto-conical pole face provided by the core, said pole faces providing an air gap located approximately centrally with respect to the windings.

17. In a system of controllin'g an overdrive 'for automotive vehicles, the combination of aligned, tubular, solenoid core and armature members, a sun-gear-locking-pawl rod extending through said members, electromagnet windings surrounding said members, a stop for limiting movement of the armature away from the core, a spring surrounding the armature for urging the armature against the stop, a spring within a tubular recess of the armature for imparting movement from the armature to the rod, and a common member adjustable along the armature and providing an operating connection between said springs and the armature, and between the armature and said limiting stop, adjustment of said common member varying the position of the rod normally with respect to the core.

18. The combination of claim-17 in which the common member is a nut threadedly adjustable along the armature and having shoulder portions engaging said springs.

19. The combination of claim 17 in which the common member is a nut threadedly adjustable along the armature and having an internal annular flange engaging the spring within the armature and having an external annular flange engaging the spring surrounding the armature.

20. The combination of claim 1'7 in which the electromagnet windings comprising a main energizing coil and an auxiliary or holding coil and in which a switch is provided for opening the circuit of the main coil, said switch having an operating member located in the path of movement of -.-said common member.

21. 'Ihe combination of claim 17 in which the armature limiting stop is provided by a plate supported by studs extending the frame work of the electromagnet which supports the core and armature.

22. The combination of claim 17 in which the armature limiting stop is provided by a plate supported by studs extending the frame work of the electromagnet which supports the core and armature and in which the plate carries a switch operated by the pawl rod for controlling a circuit of the system.

23. The combination of claim 17 in which the armature limiting stop is provided by a plate supported by studs extending the frame work of the electromagnet which supports the core-and armature and in which the frame work of the electromagnet supports a switch having an operating member actuated by the common member.

24. In a system of controlling an overdrive for automotive vehicles, the combination of a base plate, a magnetizable cup attached to the base plate, the end wall of the cup being apertured, a tubular magnetizable core seated within said aperture, a non-magnetizable tube surrounding the core and extending beyond the cylindrical wall of said cup, magnet windings surrounding said tube, a magnetizable cover plate enclosing said windings and attached to the peripheral edge of the cup, a magnetizable bushing supported by the cover plate centrally thereof and supporting the non-magnetizable tube, a tubular, magnetizable armature member in said tube and extending outside said cup, a magnetizable sun-gear-locking-pawl rod extending through-said core and armature, a nut threaded externally on said armature, studs extending parallel to the armature and supported by the cover plate, a second plate supported by the studs in spaced relation to the cover plate, said second plate providing a stop engaged by said nut. a spring surrounding the armature and confined between the nut and the cover plate, a spring within the armature and surrounding the rod and confined between the nut and a shoulder provided by the rod, a switch on the cover plate controlled by said nut and a switch on the stop plate controlled by said rod.

25. In apparatus for controlling an automobile overdrive having planetary gearing including a sun gear, the combination comprising a sun-gear 20 looking pawl, a spring normally holding the pawl in non-locking position, means for moving the pawl into locking position against the action of said spring, means for rendering the pawl moving means inoperative and for rendering the engine inoperative to apply torque to the overdrive to permit the spring to retract the pawl and for automatically restoring the engine torque after the lapse of a predetermined time interval independently of movement of the pawl to non-locking position.

26. In apparatus for controlling an automobile overdrive having planetary gearing including a sun gear, the combination comprising a sun-gear locking pawl, a spring normally holding the pawl in non-locking position, a solenoid for moving the pawl into locking position against the action of said spring, means under the control of the driver for rendering the solenoid inoperative and for causing the automobile engine ignition apparatus to be non-operative whereby the engine is inoperative to apply torque to the overdrive, and means independent of the driver for automatically restoring operation of the engine ignition apparatus after the lapse of a predetermined in terval of time independently of movement of the pawl to non-locking position.

27. In apparatus for controlling the overdrive of an automotive vehicle propelled by an internal combustion engine having electrical ignition apparatus, the combination with the sun-gear oi the overdrive mechanism of a sun-gear locking pawl, a spring normally holding the pawl in nonlocking position, means for moving the pawl into locking position against the action of said spring, a current source for operating the ignition apparatus, means for rendering the pawl moving means inoperative and for disconnecting the ignition apparatus from the current source so as to render the engine inoperative to apply torq ue to the overdrive to permit the spring to retrmt the pawl and for automatically restoring the connection between the current source and the ignition apparatus after the lapse of a predetermined time interval independently of movement of the pawl to non-locking position.

28. In apparatus for controlling the overdrive of an automotive vehicle propelled by an internal combustion engine having an electrical ignition apparatus, the combination with the sun-gear of the overdrive mechanism of a sun-gear locking pawl, a spring normally holding the pawl in nonlocking positionpa solenoid for moving the pawl into locking position against the action of said spring, a current source for operating the ignition apparatus and solenoid, means for controlling the circuit between the current source and solenoid, and means for controlling connections between the current source and ignition apparatus and operating during a predetermined time circuit.

'29. In apparatus for controlling the overdrive of an automotive vehicle propelled by an internal combustion engine having electrical ignition apparatus, the combination .with the sun-gear of the overdrive mechanism of a sun-gear locking pawl, a spring normally holding the pawl in nonlocking position, a solenoid for moving the pawl into locking position against the action of said spring, a current source for operating the ignition apparatus and solenoid, meansfor concurrently opening and closing a circuit between the current source and solenoid and a circuit between the current source and ignition apparatus, and

' means rendered operative by said first means for opening a circuit between the current source and ignition apparatus and operating for a predetermined time interval after the actuation of said first means into circuit-opening position for maintaining the ignition circuit open so as to render the engine inoperative to apply torque to the overdrive to permit the spring to retract the pawl and finally operating to close the ignition circuit.

30. In apparatus for controlling the overdrive of an automotive vehicle propelled by an internal combustion engine having electrical ignition apparatus, the combination with the sun-gear of the overdrive mechanism of a sun-gear locking pawl, a spring normally holding the pawl in nonlocking position, a solenoid for moving the pawl into locking position against the action of said spring, a current source for operating the ignition apparatus and solenoid, means for concurrently opening and closing a circuit between the current source and solenoid and a circuit between the current source and ignition apparatus, and a relay switch rendered operative by said first means for opening a circuit between the current source and ignition apparatus and having time lag provisions which delay the closing of the relay switch until after a predetermined lapse of time subsequent to the actuation of the first named means into circuit-opening position.

31. A system of control for automobile overdrives comprising the combination of a current source, a solenoid for controlling operation of the overdrive mechanism, engine ignition apparatus operated by the current source, a controller, a normally closed i nition circuit-making device, electrically operated means connectible with said current source for opening said ignition-circuitmaking device and having provisions for delaying the reclosing of said device when said means is disconnected from the current source, means responsive to the operation of the controller into one position for causing the current source to be connected with the solenoid and with the ignition apparatus independently of said normally closed ignition circuit-making device and with the electrical means for opening said normally closed ignition circuit-making device.

32. A system of control for automobile overdrives comprising the combination of a current source, a solenoid for controlling operation of the overdrive mechanism, engin ignition apparatus drives comprising the combination of a current source, a solenoid for controlling operation of the overdrive mechanism, engine ignition apparatus operated by the current source, a control circuit, and electromagnetic means including a pair of normally open contacts for connecting the current source with the solenoid when the control circuit is completed and including a pair of normally closed contacts ior controlling the ignition apparatus, and having provisions for delaying the return of the ignition controlling contacts to closed status for a predetermined time following the opening of the control circuit.

34. A system-\of control for automobile overdrives comprising the combination of a current source, a solenoid for controlling operation of the overdrive mechanism, engine ignition apparatus operated by the current source, a control circuit, an electromagnetic relay rendered operative by the closing of the control circuit for connecting the solenoid with the current source, and an electromagnetic relay operating contacts for controlling the ignition apparatus, said last named relay being energized in response to operation of the first relay, and said last named relay having provisions for delaying the return of the ignition controlling contacts to normal status for a predetermined time following the opening of the control circuit.

35. A solenoid mechanism for use with a motor vehicle transmission mechanism having planetary gearing including a sun gear and, a control mechanism for said sun gear comprising a. pawl hii'table to and from a projected position wherein it is adapted to hold said sun gear against rotation to a retracted position wherein the sun gear is free to rotate, said solenoid mechanism including aligned tubular core and armature members, an operating rod extending through said members, coupled at one end to said pawl, and having a head adapted to be engaged by the armature during retraction thereofifor retracting the pawl, said armature having a tubular recess receiving said head, a spring in said recess, operatively interposed between the armature and said head, for yieldingly urging the rod in pawl projecting direction under energized action of the armature, and a spring acting against the armature for retracting the same.

36. A solenoid for use with a motor vehicle transmission mechanism having planetary gearing including a sun gear and a shiftable element operable to hold or release said sun gear, said solenoid comprising aligned tubular core and armature members, an operating rod extending through said members, coupled at one end to said element and having a head adapted to be engaged by the armature for transmitting move ment from the armature to said rod, said armature having a tubular recess receiving said head,

38. A solenoid for use with a motor vehicle transmission mechanism having planetary gearlng including a sun gear and a shiftable element operable to hold or release said sun gear, said solenoid comprising aligned tubular core and armature members, said armature being located adjacent the end of the core remote from said element of the transmission and provided with a recess, an operating rod extending through the core and into the recess of the armature and attached at one end to said element, a spring in the armature recess for yieldingly transmitting motion from the armature to the rod to cause said element to move in one direction when the solenoid is energized and the armature moves toward the core, a spring located adjacent the.

armature for moving it away from the core when the armature is deenergized, and means for transmitting motion from the armature to the rod to move said element in the other direction.

operable to hold or release said sun gear, said solenoid comprising aligned tubular core and armature members, said armature being located adjacent the end of the core remote from said element of the transmission and provided with a recess, an operating rod extending through the core and into the recess of the armature and attached at one end to said element and having an abutment member located in the recess and engaged on one side by the armature when the armature moves away from the core, a spring located adjacent the armature for moving it and the rod and the element into sun gear releasing position when the solenoid is deenergized, and a 

